Through field experience in pipe bursting of cast iron water pipes, it has become clear that severely tuberculated pipes are normal. Tuberculation is a buildup on the interior wall of the pipe. The buildup is mineral in composition, and is a component dissolved in what is termed ‘hard water’. The buildup is structural rather than granular in form and is firmly attached to the wall of the pipe. It can and regularly does become significant enough to cause flow restriction due to the loss of cross sectional area. Homeowners know the buildup as lime, and there are caustic products available to remove the buildup without need for mechanical attack. While the buildup may not create any issues for daily consumer use, water pipes are sized for fire service requirements, not a common use, but a critically important need. With the tuberculation cutting maximum flow rates, the fire department may not get enough water in an emergency to serve their needs.
A very workable solution is to replace the internally encrusted pipe with a new HDPE (High Density Polyethylene) pipe using pipe bursting. This pipe is impervious to corrosion and is generally not susceptible to mineral deposits. As an alternative to replacement, the pipe owner may opt for a maintenance program, specifically removal of the deposits and potentially a follow-up process to line the pipe. This program can not be accomplished safely with the use of chemicals as they are caustic. Residual chemicals, loose deposits and water with unpleasant taste are not acceptable to the consumer, therefore a more elegant and palatable solution must be found. The present invention addresses that need.
It is a purpose of this invention to bring to market a method that removes the buildup, conveys it out of the pipe, and leaves the pipe in a sanitary condition. Upon completion the pipe may be reinstated, or more conservatively tested for sanitary condition before being returned to service. Additionally, the pipe may be lined with a product such as Cempipe before reinstatement.